On Tuesday, the board eliminated fluoride despite pleas from dentists who said its absence would cause more rotten teeth.

Credit tea party activism for the reversal.

The tea party movement took flight in 2009 in opposition to big government programs on the national stage, but its influence has since trickled down to local governments to affect the most basic of services — right down to the water that pours from your tap.

"What you see is the rise of the new conservatism," said Todd Pressman, who lobbies county government. "I think it's the tea party, but it's also the mood shifting across the country. … The tea party is the tip of the sword."

A blast of conservatism in 2010 helped elect Commissioner Norm Roche, who put fluoride elimination on the agenda this year. Then the tea party's brand of hands-off government helped persuade Commissioner John Morroni to change his stance from 2003 and join a 4-3 vote Tuesday against fluoride.

Most American medical groups strongly advocate adding fluoride to drinking water to improve dental health, particularly for needy children. A majority of U.S. communities provide fluoridated water.

Pinellas County provides water to about 700,000 people in the unincorporated areas and to most cities. Some officials in those cities were baffled by the decision to eliminate fluoride.

Former County Commissioner Ronnie Duncan chastised commissioners for wrongly siding with tea party members.

"We've got big problems in this county and that's the best they can do?" he said, noting unemployment and housing troubles.

The decision also triggered national attention with calls to the county commissioners from USA Today, CBS radio news and other outlets. Pinellas County's decision was criticized by one top U.S. official.

"We're disheartened by that," said Dr. William Bailey, chief dental officer of the U.S. Public Health Service and acting director of the division of oral health for the Centers for Disease Control and Prevention. "The CDC's position is all communities should receive the benefit of fluoridated water."

Several dozen e-mails from the public to commissioners were evenly split over the vote, echoing divisions during the Tuesday meeting. Clearwater, Pinellas Park and Largo officials said they had no immediate plans for any changes on their own to the water supplied to them.

Morroni, Roche and the two other commissioners who voted against fluoride, Neil Brickfield and Nancy Bostock, stood by the decision.

They cited conflicting answers from dentists and major health groups about fluoride, such as whether topical use was better than drinking it in water.

Skeptics and tea party members scoffed at national health organizations' support of fluoride, noting questions and resistance in other countries.

Roche's opposition to fluoride has been consistent, Duncan said. But Morroni?

"Morroni, I have no clue where he came from. Frankly, he caved to the tea party," said Duncan, a Republican whose support of rail has put him at odds with tea partiers.

Morroni said he was better informed Tuesday than he was in 2003, though he could not provide any research that swayed him.

Former County Commissioner Bob Stewart, who voted for the practice in 2003, questioned Morroni's switch.

"John was involved in the whole vetting process. I was looking for new information — something scientific — that might be such a compelling reason to change a vote on such an important decision," Stewart said. "I didn't find that.''

But Morroni said the county's role should not be doling out medicine, no more than the federal government should mandate health insurance or state governments require immunizations.

"If it was so required for everybody, why isn't the entire country doing it? People are not dying because they don't have fluoride," Morroni said. "If you take care of yourself, go to the dentist, brush your teeth, you're going to be okay."

Brickfield, Roche and Bostock objected to not giving people a choice about fluoride. Brickfield said dental health overall has improved, allowing people more options to prevent cavities.

All four Republicans said they spoke with personal dentists or pediatricians, none of whom opposed fluoride.

Tuesday's vote would not have been possible without the board's makeup becoming more conservative. It started in 2008 with Brickfield replacing Duncan and Bostock taking Stewart's seat.

Then Roche — who defeated fluoride supporter Calvin Harris — and tea party members arrived at meetings.

Roche, a former utilities employee, had opposed adding fluoride since the original vote. With a spot on the dais this year, he used another method to attack it: the budget.

This summer, he proposed ending funding for fluoridation, which cost the county $205,000 a year. Other commissioners resisted but agreed to hold Tuesday's meeting.

Commissioners downplayed the role played by the tea party, noting complaints about fluoride had continued over the years.

But it was evident Tuesday that the issue had gone beyond just the safety of fluoride — and was now about the role of government in providing it.

"What we asked from them as a board is that when the buck stops with them, they take a conservative stance and spend tax payers' money wisely," said Kris Gionet, a Gulfport nurse and one of the organizers of Pinellas Patriots, a tea party group.

But observers of the county government rued a national shift that has reached Pinellas.

"I think the tea party has engulfed themselves or surrounded themselves with conspiracy theorists," Duncan said.

Times staff writers Stephen Nohlgren, Will Hobson, Richard Martin and Keyonna Summers contributed to this report. David DeCamp can be reached at ddecamp@sptimes.com or (727) 893-8779. Follow him on Twitter at twitter.com/decamptimes.